I took these images yesterday no more than a couple hundred meters from each other. They were taken near Le Teich, a Parc Ornithologique reserve which, according to the fatbirder website, is supposed to be France's answer to the UK's Minsmere. The reserve in fact held limited birdlife, no dragonflies or butterflies at all. These shots were taken outside the reserve on the edge of the sandstone conifer forest. It was just pure chance that we should find both Long-tailed Blue and Short-tailed Blue so close to each other.
EXIF Detail: Aperture F/11. ISO 500. Exposure -0.7EV. Shutter 1/200s. Matrix metering. Lens: 105mm macro hand held.